Jakub J. Koston Switching
Switching The process of connecting the sending host, the medium and the receiver host with physical or pseudo-physical switches. Circuit Switching ''' The whole network of systems (telephones) is connected where nodes and physical switches are implemented to switch between different users to establish a line of connection. Establish, Transfer and Disconnect Phase one, the establishment of the line of communication between two users is where the caller and the receiver are connected by nodes in a network. This takes time as physical switches are moved to connect the two users. Phase two, data transfer and communication where a stable and secure line is established between the two users and is not able to be altered by other users until the connection is complete. Phase three, disconnecting the two connected users by clearing the nodes of their established locations to allow them to freely move around and connect the next two users. Advantages When a connection is established between two users, the full bandwidth is enabled for them and they will not be disconnected from each other. The connection is stable for as long as the two users are connected and their connection will not be changed or accessed by any users as they are cut off by the nodes. Disadvantages A connection between more than two different users cannot be physically established as two of the users are physically connected using the circuit line. Also, the connection establishment time is high, and therefore the line is busy for the duration of not only the communication but also the establishment and successful disconnect time. This is the slowest way of communicating between two users as the slowest node will slow down the fastest node because they cannot communicate faster than the slowest node. '''Packet Switching Packets are data blocks of appropriate size that can be sent over a large networks due to their header property that defines their destination. This allows them to be read by the network and sent to the appropriate users without large delay as no other user will be forced to access them. The nodes will send the packets along their network until the receiving user is reached. Advantages Packet switching sends the packets along the nodes to the end users along many paths. Like sending a set of cars to a factory, each packet will find its own path to the user and once they find an efficient path and are received the next packet will follow the paths to get to the receiving user and despite the traffic the packets will get around different transfers very quickly as there is no physical switch that is reserved for each transfer until disconnect. Also, if a single node is damaged only a small loss of packets will occur as packets have many paths. Packets are digital data and therefore do not have to be converted which saves time. Disadvantages Packets may become missing during transfer due to a damaged node or a faulty communication line because of their static path nature. Packet switching requires much more power as well as RAM to handle the higher complexity of the protocols of packet switching as well as the speed and size of the packets are being sent. There is data transmission delay as the packets will be temporarily held in the nodes until a line is available. Datagram Approach Individual packets with the same destination that are separate from other packets that have their own speed and travel their own path. This is the fastest way of sending data as all the packets will travel across many paths of nodes, therefore not all the packets will be affected by traffic. Virtual-Circuit Approach 'Circuit switching with packets' as a path is established between two users and then many packets of data are sent to or between the users. This is better than circuit switching as packets are stored temporarily on the node between the two users until a communication line is free for transfer.